SET-TRACE-EVISC-TUPLE

A trace evisc-tuple, which is set by this utility, provides a means to
restrict printing during tracing. See evisc-tuple for an introduction to
evisc-tuples; also see set-evisc-tuple and see set-iprint.

By default the ACL2 trace mechanism, trace$, automatically deals
with stobjs, the logical world, and certain other large structures.
See trace$, in particular the documentation of trace$ option :hide.
However, even with that default behavior you may want to restrict what is
printed according to the print-level and print-length of an evisc-tuple;
see evisc-tuple.

See trace$ for a discussion of ACL2 tracing. The evisc-tuple used by
that trace utility is the one last installed by set-trace-evisc-tuple
(or by set-evisc-tuple for the trace-evisc-tuple) -- initially to the
default of nil -- unless overriden by trace option :evisc-tuple.

Remark. If you use value t, then ACL2 will ensure that the logical
world and stobjs are kept up-to-date in the trace evisc-tuple.